340 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XIV. 



region, and the supracaudals behave as is the rule with other snakes, and 

 which I have just mentioned. In Bungarus, however, the enlarged and 

 hexagonal characters of the vertebral row are preserved in the median row 

 of the supracaudals, subject to some modification in size at the various steps 

 where blending occurs. 



Keels, 



The carination of scales is so capricious in the same specimen, though 

 fairly constant in like species, that it deserves far more mention than has 

 been conceded to it. Such remarks as " keels present" or "absent" have 

 little weight unless these remarks are qualified. In some snakes they are 

 present on every scale from the parietals to the tip of the tail (excepting 

 perhaps a few in the forepart of the ultimate row), as in Ancistrodon 

 himalayanus, Cerberus, Echis, &c.; in others they cease before the supra- 

 caudals have dwindled to two rows as in Tropidonotus piscator and 

 stolatus, and in others they cease before the fours are established as in 

 Trimeresurus gramineus, &c. In others they disappear before the sixes as 

 in Zamenis mucosus and korros. The numbers of rows that are keeled 

 should be recorded in all the three sites where scales are counted (see 

 above). Before deciding whether keels are present or absent, the supraanal 

 region is ihe part to be specially examined. Often scales are keeled here 

 where they are smooth elsewhere as in TJryophis, where the median rows 

 are specially so distinguished, and in Hypsirhina plumlea and some Aspidura, 

 where the lateral rows exhibit this character. In all cases where faint 

 keels are present these are most apparent in the supraanal region. 



The Rosteal. 



Such expressions as " visible from above '' are not precise, since all rostrals 

 are more or less visible from above and the degree of visibility is subject to 

 some variation. It is better to compare the portion visible from above 

 with the scale or suture in the median line immediately behind it. Thus it 

 is often twice as long as the suture between the internasals, as in many 

 Simotes and Oligodon, often about equal to that suture, as in Xenopeltis, 

 &c., and often half or less, as in Ancistrodon. The number of sutures 

 it makes with adjacent scales should be mentioned. In a key such a 

 remark as "rostral in contact with four scales" is easily grasped and as 

 easily investigated. These sutures may be four only, as in the majority of 

 the Hydrophiince (except the genus Platuriis), Xenopeltis and many Uropeltidoe; 

 five as in Typhlopidce, Helicops, Gerardia, Fordonia, and Hip'istes ; six, 

 as is the rule, such as in Zamenis and Dipsas ; and rarely eight, as iu 

 Simotes splendidus. 



Another point is the relative length of these sutures. When they are six, 

 which is usually the case, the nasal is usually the largest as in many Bun' 

 garus, Zamenis, &c. In some snakes this suture may be twice that of the 

 internasals or more, as in Dryophis, Ancistrodon himalayanus, and Vipera 

 russellii. Sometimes the internasal and nasal sutures are sub-eqnal, and this 



